The use of various scrubbing apparatuses and techniques for the removal of particulate matter and gaseous contaminants from air streams, in order to maintain a desired level of pollution control or product recovery, is well known. It is usually most desirable to remove particulate matter from gaseous combustion products, such as fly ash, as well as acidic gases, such as the oxides of sulfur or nitrogen, at high efficiencies and with low pressure drops. The removal of particulate matter and gaseous contaminants from oil-fired boilers, used for steam-flood secondary recovery in oil fields, is also desirable, but presents additional problems, because secondary recovery usually is a transient operation, taking place at one well or a few wells in remote locations.
Therefore, it is desirable to provide for a simple, effective, high-efficiency, low-pressure-drop, wet scrubber apparatus and method, particularly one which is economical and preferably skid-mounted or compact and portable, so that it may be moved economically and with ease from one well location to another well location.
One of the techniques for the scrubbing of particulate matter and effecting contact of a gas with a liquid is set forth, for example, in U.S. Pat. No. 3,803,805, issued Apr. 16, 1974, which describes a method of removing particulate material from gas streams through the use of at least one jet in a vertical column directed countercurrently to the gas within the vertical column, with the velocity of the liquid from the jet being of sufficient power and the gas-stream velocity maintained at a sufficient level over and above the flooding velocity of the liquid from the jet; that is, above the velocity necessary to suspend the liquid in the gas stream, creating, in effect, a reverse-jet apparatus. The technique disclosed, while effective in some respects, often requires a high expenditure of horsepower per square foot of a cross-sectional area, with the pressure drop being higher than desirable for some scrubbing operations, and with lower efficiency than is often desired in connection with effective removal of particulate matter and the removal of gaseous contaminants from the gas stream.
Therefore, it would be desirable to provide for an improved reverse-jet scrubber apparatus and method which overcome some of the disadvantages of the prior-art jet scrubber apparatuses, and also to provide for an improved reverse-jet scrubber apparatus having a high efficiency with a low pressure drop, and which operates with low energy requirements and reduced amounts of scrubbing liquid.